Mercury switch



May 8, 1951 G. A. ONDA ETAL MERCURY SWITCH Filed Oct. 8, 1949 INVENTOR. FPA/VK K LADA/VVL BYGEO/PGE ,4. NBA.

Patented May 8, 1951 MERCURY SWITCH George A. Onda and Frank K. Ladanyi, Cleveland, Ohio Application October 8, 1949, Serial No. 120,37 8

This invention relates in particular to a new design and useful improvement in mercury switches.

The primary object of this invention is to provide a device in the form of a mercury switch for use on tractors, or other motor vehicles, in combination with a relay, as a safe and efficient means for making and breaking a circuit passing through such switch. i

A further object is to provide a switch of the class described which will not respond or activate to the ordinary vibrations incidental to a tractor or other motor vehicle, while traveling over rough ground or surfaces and thus interfere with the normal operation and travel of such vehicle.

A still further object is to provide a switch of the class described which will only activate to the extent of closing a circuit passing through such switch when the tractor, or other motor vehicles, in which such switch is installed, assumes a dangerous tilting or rearing upward position.

Other uses and advantages in the use of the invention will be readily discernable from the description and a reference to the accompanying drawing, in which:

Fig. l is a vertical sectional view taken lengthwise of the device.

Fig. 2 is a cross sectional view of a segment of the device looking at it from underneath.

Fig. 3 is a side plan view of a segment of the device, the same segment as shown in Fig. 2, with the ports 2A positioned as a time element.

Fig. 4 is a view similar to that shown in Figs. 2 and 3, showing an adaptation of the device for the use of two bafiles in place of one.

Fig. 5 is the same view shown in Fig. 4, with the ports 2A positioned to operate as a time element.

In the drawings: A is the invention or device, having a solid closed end 3 and the opposite end closed by the sealed in part 2, l is a body of mercury inclosed between the ends 2 and 3, 4 and 5 are electrical wires with insulations, 4A and 5A respectively, inserted and positioned in the part 2, 2A are cylindrical formed transverse ports through 2 and separated by the wall 6 as a bafile, as shown 2C are passage ways around the ends of the baflle 6 to permit communication between the ports 2A, 2B is a central opening or port connecting the interior of the body A with the port 2A adjacent to the end of 2B.

The position of the ports 2A in Fig. 3 is slightly diflerent from their position in Fig. 6, such position of the ports retards the flow of the mercury from the port 2A, connected with 23, around the 1 Claim. (Cl. 200-33) 2 battle 6 through 20, thus acting as a time element.

Fig. 4 shows a further use of the device by having three ports 2A and two baflles 6 provided in part 2. This arrangement acts as a timeelement as it will require more time and pressure of the mercury to reach the third port in order to make contact, with the terminal wire 4, in Fig. 5, the ports 2A are positioned in a manner similar to the ports in Fig. 3, and for the same purpose.

The action of a mercury switch is well known to those familiar with the art, however, a further brief description of the parts of the device and the manner of functioning will render the device more easily understood by those interested.

Mercury being a metal provides an excellent medium for the transmission through it of an electrical current, or energy. This property of mercury is the activating element of the device. With the device properly installed and positioned on a tractor, or other motor vehicle. The device will not operate by the ordinary vibrations of a tractor traveling over a rough surface, or ground which produces mere splashes of the mercury within the device, however, when such tractor, or other motor vehicle rears upward or assumes a dangerous side tilting position, the mercury within the body of the switch will then flow through the opening 2B into the communicating port and around the baffle 6 through the passage 20, into the adjoining port 2A contacting the wire terminal 4 therein thus closing the circuit through such wires and, in conjunction with a relay, cut off the electrical energy to, and stopping, the motor, thuspreventing possible damage to the tractor or vehicle, or injury to the operator, or

both.

The invention as described and shown in the drawings, when properly positioned on a tractor, or other motor vehicle, will, in conjunction with a relay provide a safe, sure, and efiicient means for shutting off the electrical current, or energy in a tractor or other motor vehicle, and stopping the motor, when such vehicle tends to rear upward and is in danger of turning over backwards, damaging the tractor both by a possible fire from the ignition system or otherwise, and injuring the operator also, however, by the invention functioning as described, all such probable damage and injury is prevented. Also, it will be quite obvious from the fact that such switch when connected in an electrical circuit with a relay in a proper manner, so that when the vehicle is righted after the current has been shut oil the relay will operate to re-energize the ignition to place the vehicle in operation again.

The use of several parts with bafiies positioned between them as shown in Figs. 4 and 5 provides a time element in the operation of the switch as it will require more time for the mercury to reach its bridging position by reason of the delays caused in passing such baffles. This is an important feature of the switch for the reason that in the event a motor vehicle provided with such switch, suddenly tilts to one side and then almost immediately rights itself, the mercury in such case would require more time to reach its bridging position so that due to such time element the current is not unnecessarily cut off, the vehicle righting itself and not requiring the switch to operate as a safety means.

The invention may have several forms of structure as relates to the ports 2A and the baffles 6. In Fig. 1, is shown with two such ports in parallel alinement which permits a quicker flow of the mercury into such ports, when the switch is activated as described than shown in the other figures.

In Fig. 3, the two .ports 2A are shown somewhat out of alinement in which position the mercury being somewhat retarded in reaching the outer parts acts as a time element in the functioning of the device.

In Fig. 4, the invention is adapted to use three ports 2A in parallel alinement, such arrangement of structure also acting as a time element in the functioning of thedev-ice.

Fig. 5, the invention is adapted to use three ports 2A arranged somewhat out of alinement which, similar to the arrangement in Fig. 3, acts in retarding the :flow-of the mercury throug-h.such parts, as a longer time element than in Fig. 3.

The device is preferably made of plastic or other similar and suitable-material.

In the installing of the switch on a tractor, or other motor vehicle, one switch is positioned to functionwhen such vehicle tends to rear upward, or upward and backward, and two positioned to function when such vehicle tilts sidewise.

It will be observed from the foregoing descrip i,

tion that We have invented a novel, useful, and eflicient device and while we have shown the invention in desired and useful form and structure, we wish to be understood that further adaptations in its use may require modifications without departing from the basic features or spirit of the invention.

What we claim as new and desire to secure by Letters Patent is A mercury switch, comprising a tubular body closed at both ends thereof by means of sealed in end parts, said body providing a cavity in which mercury is disposed and free to flow from :and return torsaid cavity, one of said end parts having electrodes sealed therein and having two cylindrical parts extending parallel and transversely through same, a mercury flow bafile positioned between said parts, said bafile having a passage around both ends connecting said parts, a central opening throughsaid end .and between the said inner part and the said body cavity to permit the flow of the mercury into said inner part and around said baffle throughsaid ,passage into the adjacent part, said mercury thus bridging the said electrodes by reason of the tiltin .of said body to cause the mercury to rise to the level of said central openings and flow throughsame.

GEORGE A. ONDA. FRANK K. LADAN YI.

REFERENCES CITED The following references :are of record in :the file of this patent:

UNITED STATES PATENTS Number Name Date 2,010,398 Keen .-Aug. .6, 193.5 2,182,216 tStaley Dec. 5., L939 2,192,262 Griesedieck Mar. 5, 19.40 2,194,873 Schaer Mar. 26,1940 

